<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    *{
      margin: 0;
      padding: 0;
    }
    html,body {
      width: 100%;
      height: 100%;
    }
#header{
height: 100px;
background: hotpink;
}
#content{
  height: calc(100% - 100px);
  background: khaki;
}
.left{
  width: 200px;
  height: 100%;
  background: green;
  float: left;
}
.right{
  height: 100%;
  background: blueviolet;
  overflow: hidden;
}
  </style>
</head>
<body>
 <div id="header"></div>
  <div id="content">
    <div class="left"></div>
    <div class="right"></div>
  </div>
</body>
</html>